Intraductal papillary neoplasm of the bile duct: A biliary equivalent to intraductal papillary mucinous neoplasm of the pancreas?

IPNBs are an uncommon variant of bile duct cancer, representing approximately 10% of all resectable cases. They occur throughout the biliary tract, share some histologic and clinical features with IPMNs of the pancreas, and may represent a carcinogenesis pathway different from that of conventional bile duct carcinomas arising from flat dysplasia. Given their significant risk of harboring invasive carcinoma, they should be treated with complete resection.